properties of radio-isotopes

1. PROPERTIES
OF
RADIO­
ISOTOPES
by:­ Aman Verma

2. Emits Radiation
●
Radioactive isotopes are unstable so they go
into a radioactive decay emitting radiations.
●
Till they become stable
●
3 types of radiations:
Alpha particles (α)
Beta particles (β)
Gamma particles (γ)

3. Radiation

4. Half-life (t1/2)
●
●
The time taken for the activity of a
radioisotope to reach half of it's original value.
Thus activity decreases with time.

5. Half-life (t1/2)
For example, suppose we had 20,000 atoms of a radioactive
substance. If the half-life is 1 hour, how many atoms of that
substance would be left after:
Time
(after)
Number of atoms
remaining
% of atoms remaining
1 Hour (one lifetime)
10,000
50%
2 hours (Two
lifetimes)
5,000
25%
3 hours (Three
lifetimes)
2,500
12.5%

6. Half-life & Radioactivity

7. Penetration Property
●
●
Radioactive radiations have different
PENETRATING ability.
Depends on ''thickness and density'' of
material

8. Penetrating Power of Radiation
α
β
γ
n
Skin &
paper
5mm brass
6mm Al
α = alpha β = Beta
Pb & concrete
Very thick
concrete (2m)
γ = Gamma n = Neutron

9. Same Chemical properties
●
●
Isotopes of same element have same
Chemical properties.
Due to same no. of electrons in the 'Outermost
Shell'.

10. Different Physical properties
●
Differ from isotopes to isotopes.
●
Based on number of neutron.

11. Different Physical properties
●
Differ from isotopes to isotopes.
●
Based on number of neutron.